1. Technical Field
The present invention relates to bench-center instruments and more particularly to the conversion of a V-block measuring and gauging instrument into a bench-center instrument.
2. Background Art
V-block measuring and gauging instruments for measuring the length, diameter, concentricity, out-of-roundness and the like of machined part pieces which are to be supported on their surface (e.g. on bearings) are known in the art. One such instrument which may be located next to a machine tool for use by the machine tool operator to measure machined pieces immediately after machining is shown in my U.S. Pat. No. 4,064,633.
V-block measurements however have limited value with machined pieces which are to be supported between centers. It is preferable that measurements of such pieces be made by a bench-center instrument which supports the pieces on centers when measurements are taken. Bench-center instruments for taking such measurements are also known, one of which is shown in my U.S. Pat. No. 4,064,633.
The prior art instruments generally cost in the many hundreds and even thousands of dollars. Further, the prior art instruments, particularly bench-center instruments, are bulky, taking up a large space wherever they are located. This in many cases can prevent the instruments from being located near the machine tool where the machine tool operator may readily use them. Space limitations can be a particular problem where both V-block and bench-center instruments are required.
Still further, live centers of prior art bench-center instruments have been somewhat difficult to operate, requiring that the operator use two hands to prevent the instrument from tipping over or sliding on its supporting surface.
Further, the prior art instruments have encountered difficulty in that their components are sometimes inadvertently and undesirably moved from positions intended to be fixed for repeat measurements.